Well the secret is, just as you suspected, in the lighting. If you blow out a white background, then you won't see any wrinkles. If you underexpose a black background, then you won't see any wrinkles.
If you shoot RAW, you can often take the background to white or black by adjusting the White or Black point. In PS CS2, you can do this visually. If you'll see my tutorial on my RAW workflow in the Digital forum, I talked about the visual method.
Cheers,
rfs